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<html lang="en">
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    <meta charset="UTF-8" />
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    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      let arr = [1, 2, 99, 3, 4, 5];

      //   方式一
      /*  let max = arr[0];
        let min = arr[0];
        for (let i = 1; i < arr.length; i++) {
          if (max < arr[i]) {
            max = arr[i];
          }
          if (min > arr[i]) {
            min = arr[i];
          }
        }
         */

      //方式二
      /* let max = Math.max.apply([], arr);
        let min = Math.min.call([], 1, 2, 99, 3, 4, 5); */

      //   方式三
      Array.prototype.getMax = function () {
        let arr = this;
        let max = arr[0];
        for (let i = 1; i < arr.length; i++) {
          if (max < arr[i]) {
            max = arr[i];
          }
        }
        return max;
      };
      Array.prototype.getMin = function () {
        let arr = this;
        let min = arr[0];
        for (let i = 1; i < arr.length; i++) {
          if (min > arr[i]) {
            min = arr[i];
          }
        }
        return min;
      };

      console.log(arr.getMax(), arr.getMin());
    </script>
  </body>
</html>
